Russian President Vladimir Putin said Thursday that Russian forces had been deployed to Crimea last month to support local defense teams, the first time he has admitted such involvement by Russia.

Putin had repeatedly denied sending any forces to Crimea ahead of the March referendum there that eventually led to the region's annexation by Russia. Putin said the troops were deployed to protect Russian-speaking citizens in Crimea.

"Of course we had our servicemen behind the self-defense units of Crimea," Putin said during an annual televised call-in with the nation on Thursday. "We had to make sure what is happening now in eastern Ukraine didn't happen there."

The United States and other Western nations have accused Russia of being behind similar unrest in eastern Ukraine, promising additional sanctions if events continue on their current path. Again on Thursday, Putin denied any Russian military forces are in east Ukraine, but many have noted how the situation in eastern Ukraine is starting to play out exactly as it did in Crimea.